Baby Changing Matt

I have a situation with my friends right now and I do not really know what to do. Am friends with a girl, but all my friends are not really friends with her, and some of them hate. I do not understand why she has never done anything for them. In the past we had some problems and friends it was influenced by this girl other way to do certain things mean, but she never did anything wrong and if that was a very long time. It can be annoying sometimes, but she does not want to be mean. It is not as boring as it used to be because it matures. It is not good at making friends and I am one of the only friends she a. I am very understanding of people and am able to tolerate things that many people can not.

So, to return to the problem. She is sitting with all my friends to lunch and most just act normal to her. However, recently, at lunch, two people, Jess and Matt (name changed) were laughing at her. I told them to stop and helped her to calm down because she was very upset. But then I had a rehearsal for lunch the other day and I missed an important episode. Jess and Matt made some comments very disturbing and I was not there to stop it. My friends who are not nasty to her has not fight for it. In fact, some of them were still laughing, because apparently Jess and Matt tried to be funny. Jess took a video and a few other friends took pictures. My friend went to the administrator of the grade and steps have been taken. My friend laughs at you can not eat with Jess and Matt, which means she can not eat with our group because we all eat whole. I do not know what to do because I have many friends in this group that I would still eat with (though not Jess and Matt), however, I eat with my friend and others too, and I do not want that her to eat alone. My other problem which worries me even more is the fact that one of the witnesses of the incident is my best friend Lisa *. I trust her so much and I can not believe she would stand there and laugh. She was one of my friends who do not hate my other friend and his understanding of the type a bit more because they were good friends in the past. I felt bad and she betray me like that. As I talked about it, she felt ill and think that Jess and Matt went too far, but she thought that some of the things they did were funny. I do not really know what to do or what to think because she is my best friend and she laughed and took pictures at my other friend was obviously not fun. After the incident, everyone thought that my other friend made a big deal of nothing and they hate even more. Some of the things they did when she went to the bathroom said, "you're going to the bathroom to see if your pregnancy." Matt joked, "I've been thinking about it much, and want to go out with me." Jess and said, "you'll have babies matt". I do not know what else they said I was not there. I'm sure it got worse though. Matt also at one point grabbed my backpack and friends clung to her. She crawled around trying to shake the next day and hurt his shoulder because of it. It is also the same shoulder that she will soon undergo surgery on.

Help me with my position? What should I do? Who do I trust?

When I read that made me pity the girl, and your doing well sticking by it and not make fun of her,

to be completely honest, I stick by this girl and sit down to dinner with her and make sure it goes well because if you decide to stay with friends while others isn't this girl is going to have no she?
sit with her for a bit, try to make him make some new Frie.